Indications for Prostate Biopsy Digital Rectal Exam (DRE) suspicious for cancer at any PSA level PSA above 3 ng/mL High Risk of prostate cancer based on multiple risk factors. TRUS (transrectal ultrasound) Guided Biopsy. In some circumstances, Doppler ultrasound- guided or MRI-guided biopsy may be preferred or required. If TRUS-guided-biopsy not done, follow up in ...continue reading "Biopsy to Detect Prostate Cancer – when is it needed?"